Engine valve drive shaft



R. M. HEINTZ 2,487,872

ENGINE VALVE DRIVE SHFTA Nov. 5, 1949 Filed April 18, 1946.

RALPH M. HE/NTZ i BY- ATTO/wwwl Patented Nov.` 15, 1949 ENGINE VALVE DRIVE SHAFT Ralph M. Heintz, Clevel Jack & Heintz Precision and, Ohio, assignor to Industries, Inc., Cleveland, Ohio, a corporation of Delaware Application April 18, 1946, Serial No. 663,192

1 Claim. l

This invention relates in general to rotating shafts and more particularly to improvements in the construction and mounting of engine valve drive shafts.

One of the primary objects of the invention is to provide a simple, compact and self-contained engine valve drive shaft assembly including a drive shaft rigidly carrying a single casting which latter includes a pair of cams and a counterweight therefor as well as an improved mount and bearing construction for the shaft.

With the foregoing and other objects in view, the invention resides in the combination of parts and in the details of construction hereinafter set forth in the following specification and appended claim, certain embodiments thereof being illustrated in the accompanying drawings, in which:

Figure 1 is a plan view of the valve drive shaft with its cams and counterweight and mounted in an engine casting the interior of the casting being shown in plan and its bearing supports in section;

Figure 2 is a view in section taken along line 2-2 of Figure 1; and

Figure 3 is a view in section taken along line 3-3 of Figure 2.

Referring more particularly to the drawings, the casting l, which may be of some light weight metal as magnesium or aluminum, may have two or more bearing portions 2 and 3 for supporting the engine valve drive shaft 4. One end of shaft 4 is shown splined at 5 to receive a gear as part of a suitable gear train so as to be driven by a prime mover such as an internal combustion engine.

The shaft 4 may be of steel and the casting I of aluminum, in which case it is preferable that the inner surface of the bearing portions 2 and 3 of the casting be impregnated with indium to increase its wear resisting characteristics. The outer surfacev of the shaft at these portions, as well as the outer operating surface of the cams 1 and 8, is preferably providedr with an initial layer of bonded relatively hard metal such as silver or copper, an intermediate layer of indium and a final layer of relatively soft metal such as lead or cadmium. This eliminates the necessity for soft metal plain bushings.

As shown in detail section in Figure 3 the twd cams and counterweight are formed integrally as a single casting of metal, such as cast iron, the casting including a hollow barrel 6, to receive the drive shaft, a pair of spaced and staggered valve driving cams 1 and 8 and an intermediate, but circumferentially offset counterweight 9. This casting, including the cams and counterweight is readily removable from but rigidly carried by shaft 4. The counterweight 9 acts as a counterweight for the forces created by the eccentric rotation of both of the two cams to dampen the undesired vibrations that would otherwise be transmitted to the engine valves.

From the foregoing it -will be apparent that there has been provided an improved engine valve drive assembly to include a drive shaft that is supported by the light weight cast metal housing to the elimination of removable plain bushings. Moreover, there has been provided a pair, or more, of engine valve driving cams and counterweight therefor, the cams and counterweight being in the form of a single piece casting of cast iron readily mounted on and removable from the engine valve drive shaft.

I claim:

A drive shaft and a housing for supporting the same for rotation, said shaft having an external bearing portion formed of a plurality of layers ofY material bonded thereto and supported by the inner metallic surface of said housing, said layers of bearing material on said shaft consisting in an initial layer of relatively hard metal, an intermediate layer of indium and an exterior layer of relatively soft metal and the shaft supporting inner surface of said housing being formed of a layer of magnesium with indium impregnated therein. Y

RALPH M. HEINTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,575,239 Walker Mar. 2, 1926 1,781,474 Pierson Nov. 11, 1930 2,325,071 Murray July 27, 1943 

